"...the idea is to try to give all of the information to
help others to judge the value of your contribution; not just the
information that leads to judgment in one particular direction or
another."
Last time, I posted an ultra-simple “from scratch” RFID reader, which uses no application-specific components: just a Propeller microcontroller and a few passive components. This time, I tried the opposite: building an RFID tag using no application-specific parts.
Well, my solution is full of dirty tricks, but the results aren’t half bad. I used an Atmel AVR microcontroller (the ATtiny85) and a coil. That’s it. You can optionally add a couple of capacitors to improve performance with some types of coils, but with this method it’s possible to build a working RFID tag just by soldering a small inductor to an AVR chip
The Teensy is a complete USB-based microcontoller development system, in a very small footprint! All programming is done via the USB port. No special programmer is needed, only a standard “Mini-B” USB cable and a PC or Macintosh with a USB port.
Key Features:
USB can be any type of device
AVR processor, 16 MHz
Single pushbutton programming
Easy to use Teensy Loader application
Free software development tools
Works with Mac OS X, Linux & Windows
Tiny size, perfect for many projects
Available with pins for solderless breadboard
Comes with assembled Teensy board (ATmega32u4 with bootloader preinstalled) and header to allow easy breadboarding. We suggest using AVR-gcc (like WinAVR) with the LUFA library or ‘Teensyduino’ Be sure to check out the multiple resources available at PJRC!
DrLuke, a user at bildr, has written an in depth tutorial on the use of the 74HC595 8 bit shift register.
OK, so say you have this crazy cool idea where you need to control a ton of LEDs (I know, I know… LEDs). You looked at the multiplexer article, and that was great, but this idea is so cool, you need individual control of each LED, and turning them on one at a time just won’t do. Well again, we are here to help, and now it’s time to introduce you to the Shift Register. Not just any shift register, the super cheap, incredibly awesome 74HC595 8-bit Shift Register!
With a video, diagrams, even AVR and Arduino code samples!
Counterfeit Teensy boards have appeared on the market. Counterfeit boards are not compatible with Teensy Loader and Teensyduino, and may not work with many projects. Counterfeits may be sold as “Teensy 2.0″ but have hardware similar to version 1.0 (see below). PJRC does not provide technical support for counterfeit products! Please be careful to buy only genuine Teensy USB development boards.
Adafruit carries the real deal directly from Paul of course. We always support the maker and designer and our customers like that as well. There are likely clones of Paul’s work because there was/is a lot of demand for these because they can be used to jail break Playstation 3 units.
We thought we’d use this opportunity to discuss a related topic – open source hardware vs non-open source hardware. The Teensy is not open source hardware, while we wish it was, we respect Paul’s wishes to distribute any way he wants and retain any rights he wants. Some customers have complained about the Teensy not being open source hardware – and others have said that open source hardware is a “bad idea” because some can clone / counterfeit it so easy. So here we are, the Teensy is cloned / counterfeited and it’s not open source hardware. It doesn’t matter if something is OSHW or not – if someone wants to clone hardware they will.
We think that anything interesting may get cloned, if something is open source hardware it can be cloned too – but along the way you get community, contributions and more. Would the Teensy be cloned if it was OSHW, of course it could, but there would be an entire community who spent time and effort with a sense of ownership could help get these stores to buy directly or at least work out a licensing agreement with the makers. Maybe Paul has a trademark on the name and can work with the USA based sellers of the clones to get them to reconsider carrying the clones or changing the name. Any way, all guesses – please consider getting a real Teensy from us or Paul and supporting the maker.
We’re not sure what will happen with this example, but wanted to share it – for the people who say they will not do open source hardware because “it might” get cloned, here’s an example of hardware that was cloned that clearly was not OSHW.
Reading out the flash memory is straightforward with an AVR ISP programmer, such as the USBtinyISP, using avrdude from the command line. You’ll need to have a copy of the AVR toolchain– or at least avrdude –installed on your computer. There are easy installers available for Mac (Crosspack) and Windows (MHV AVR Tools) that include this software, along with the other open source tools for AVR development. Linux packages for AVR development are also available.
We put these back in stock today, the were taken out during some crazy PS3 hack that have have now blown over.
The Teensy is a complete USB-based microcontoller development system, in a very small footprint! All programming is done via the USB port. No special programmer is needed, only a standard “Mini-B” USB cable and a PC or Macintosh with a USB port.
Key Features:
USB can be any type of device
AVR processor, 16 MHz
Single pushbutton programming
Easy to use Teensy Loader application
Free software development tools
Works with Mac OS X, Linux & Windows
Tiny size, perfect for many projects
Available with pins for solderless breadboard
Comes with assembled Teensy board (ATmega32u4 with bootloader preinstalled) and header to allow easy breadboarding. We suggest using AVR-gcc (like WinAVR) with the LUFA library or ‘Teensyduino’ Be sure to check out the multiple resources available at PJRC!
This project tutorial will show you how you can convert a console game pad into a USB keyboard mouse for playing games on your PC. The USB game pad can be used with nearly any software, such as a MAME emulator, game, simulation software, or for custom user interfaces. We’ll start by turning the buttons of the game pad into keyboard buttons, so that pressing ‘up’ is converted into the ‘U’ key, for example. The firmware is easily adaptable, so you can adjust it for whatever software it will be used with. Then we’ll make the project more interesting by adding an accelerometer. This will allow the game pad to be used as a mouse by tilting it! This tutorial including the original code and Portal video is by Devlin Thyne! Rock!
You’ll need the following in order to build the project:
Teensy – This is a very small microcontroller board that can act as a keyboard/mouse
Triple-axis accellerometer – We’ll be using the nice ADXL335 on a breakout board. You can skip this if you’re not planning to add in the mouse capability
USB cable with mini-b connector – to attach to the Teensy for plugging into a computer!
Ribbon cable – for all the soldering connections. Rainbow cable is the easiest to work with as its color coded
Here’s a tutorial page for the FTDI friend with some information on drivers and files, we also include a little hack on using an FTDI chip as a slow but functional AVR programmer. If you’re in a pinch and need to program an Arduino bootloader but don’t want to replace the drivers and avrdude, this will work with just a single wire soldered on… FTDI Friend – Breakout Board+ (tutorial)
Connecting a microcontroller to a computer or laptop is a common problem: For decades, all computers had serial ports and parallel/printer ports. These were great for engineers because they were easy to connect to – data sent from the computer showed up exactly the way it was sent. Nowadays, few computers have parallel or serial ports, they have been replaced with USB. USB is better for users because theres only one connector, and information can be sent really fast with no errors.
But the trade-off is that USB is more complex than serial or parallel since data is wrapped in complicated, super-fast packets. So what if you still want that serial port? Well, you can use a usb-serial converter. These have little chips in them that are very specialized – they show up in your computer as a serial port but they do it through USB. The good news is that these are very common and cheap, but the bad news is that they are not very good for microcontroller hackers.
Why? For one thing, these big 9-pin cables had to reach many meters so what the designers did is make the voltage on them rather high, about 20V from negative to positive. Microcontrollers tend to want no more than 3 or 5V! Plugging this into your microcontroller will quickly damage it permanently! If you want to use one of these cables with your micro, you can build a converter from the 20V down to 5V, often called a MAX232 converter. Some cables are hackable to bring the voltage down so if you’re excited to tear apart an adapter and solder some wires that can be a solution. For most makers, we really suggest you use is an FTDI cable or adapter.
FTDI chips simply take the USB signals and output 3 or 5V cleanly, so you don’t have a risk of zapping your electronics. Another nice thing about these cables and adapter is that you can use the 5V from your computer to power a project, up to half an amp. Basically like the USB/serial adapters they show up as serial ports to your computer, but these have the right voltage levels.
We have two options for FTDIness, cables and adapters. The cables are all in one piece with plugs on either end. The FTDI chip is inside the head of the cable. The adapters are small circuit boards, you can use any miniUSB cable, and the plug in the end matches the pinout of the cable. So why would you want the circuit board? For one, its a little less expensive. Another thing is that it has visible LED that blink when serial data is sent or received, which can be handy for debugging. Another fun thing you can do with the FTDI friend is change the voltage levels for power and data from 5 to 3v or change the 6th pin from RTS to DTR which may be useful for some hacker projects.
OK one question we get a lot is whats the difference between something like the USBtinyISP programmer and an FTDI adapter? Both plug into a USB port, that is true, and both can be used to program AVR. but they are different things. The USBtinyISP and other USB AVR programmers are specially made to program raw AVR microcontrollers, just as they show up from the factory. The USBtinyISP isnt meant for sending debugging messages or other data. On the other hand, if you have a chip with a bootloader on it already, like an Arduino, you can use the FTDI friend to upload new firmware and transmit serial data for debugging or logging.
However, you can’t really use the FTDI friend to program a raw chip without a lot of effort and its pretty slow. So, for programming new AVRs, use a USBtinyISP. To bootload onto preprogrammed AVRs and pass data, use a FTDI friend.
Remember, FTDI Friend is your friend, not your FTDI enemy.
Previously, we discussed about bluetooth module used with Android Nexus One, so today, we would like to present our latest project here “Android controlled wireless lamp”, We want to do somethings meaningful with the bluetooth module with Android, so we modify a small lamp and adding the bluetooth connectivity to it.
Sometimes, we may put the phone in bedroom, and we will not know someone is calling. With the bluetooth connectivity, it can communicate with your Android phone at least 10 meters or above. You can put the lamp near your TV or anywhere you stay. Also, you can use Android as a remote control to turn on/off the lamp (or any devices).
For some reason, the 32-bit versions of these operating systems don’t prevent the unsigned drivers from being installed, although they do complain.
There are a few workarounds that involve hacking Windows or disabling digital signature checking, but thanks to a tip by user wayneft on the Adafruit support forums, I was able to make the process much more straightforward. The USBTiny drivers are based on libusb-win32. Based on some notes I found on the libusb-win32 wiki, I discovered that the latest libusb drivers contain a proper digital signature…
I used the Windows device manager to upgrade the broken drivers on my Windows 7 64-bit machine. There is still a warning that “Windows can’t verify the publisher of this driver software” but there are no more errors about digital signatures and the new drivers appear to install and work correctly.
This week, Brad wrote in with an interesting question: Can you program the ATtiny25 on one of our ‘tiny2313 target boards? And the answer is yes: you can, with just a trivial modification.
Okay, back up– a little context here. The ATtiny25 and the ATtiny2313 are examples of AVR microcontrollers, the little brains that power many of our projects.
Some good stuff for the AVR freaks up in here, Alastair writes in…
Here’s a replacement for WinAVR with up-to-date tools (since WinAVR has been abandoned, and nothing has yet been released from Atmel) & an efficiency oriented runtime library for AVR microcontrollers, for those ready to graduate from the Arduino environment.
Printable catalog (PDF)
FEED
